psychosis Flashcards
What is psychosis
clinical state of mind characterized by loss of contact with reality
symptoms
perceptual disturbances:
delusion, hallucinations
social or occupation dysfunction
negative symptoms alogia, blunting effect, avolition
delirium with acute confusion and aggression
impaired awareness, confusion, disorientation always look for cause: Drugs Infection Metabolic Trauma Oxygen Psychological
pathogenesis of psychosis
dopamine hypothesis of schizophrenia - excessive dopaminergic activity
cause of psychosis
Functional psychosis
Schizophrenia
Bipolar mood disorder
Psychotic disorders due to medical conditions
Medical conditions e.g. epilepsy, Alzheimer’s dementia, HIV, neurosyphilis
Drugs
Illicit drugs –cannabis, mandrax, cocaine, amphetamines
Prescription drugs- steroids, antiparkinsonism drugs, atropine
Other- e.g. postpartum psychosis
neuroleptics
Classical neuroleptics Dopamine 2 receptor antagonists Tendency to cause extrapyramidal side effects Atypical neuroleptics D2 & D3 receptor antagonists D2 & serotonin receptor antagonist
what are the indications of neuroleptics
schizo mania organic psychosis others nausea, vomiting anaesthesia intractable hiccups tourette's syndrome- repetitive movements that cannot be controlled
route of administration
oral
injectables- short (acute management) or long acting
adverse effects of antipsychotics
typical -inhibit serotonin and histamine receptors instead of d2 and 1
atypical- inhibit serotonin and alpha adrenergic instead of d2 only
causes of treatment failure
under dosing
malabsorption
wrong diagnoses
non compliace
which group is contraindicated
pregnancy or lactation- drugs can cross the placenta
phenothiazines excreted in breast milk
children
elderly- more susceptible to CVS and anti-cholinergic side effects
hepatic diseases -dose adjustment
phenothiazine- chlorpromazine adverse effects
Adverse effects: EPSEs, sedation, postural hypotension, anticholinergic side effects, epileptogenic, photosensitivity ,jaundice, agranulocytosis
acute dystonic reaction
spasm of muscles of the tongue, neck, face and back
stop neuroleptic and give biperiden
give benzodiazepine if necessary
parkinsonism
tremor, bradykinesia, rigidity
give anticholinergics 50-150 mg
Akathisia
motor restlessness vs anxiety, caused by excess dopamine
treatment reduce dose and add anticholinergic
change to typical antipsychotics if there are complications
complications:
dyskinesia
Neuroleptic malignant syndrome
caused by dopamine blockade in hypothalamus
present with:
Hyperpyrexia
Sweating
Unstable blood pressure
Changes in LOC (stupor or catatonia like state)
Muscle rigidity- lead overactive muscles
side effects of atypical neuroleptics
associated with QT prolongation
less EPSE
weight gain
prolactin effects
chlorpromazine contraindications and drug interactions
Contraindicated in coma, severe mental depression, severe liver impairment, significant cardiac disorders, glaucoma, bone marrow depression
drug interactions with
anticholinergics, antiepileptics, antihypertensives, antiparkinsonism drugs, CNS depressants , enzyme inducers
haloperidol adverse effects,drug interaction and contraindications
Contraindicated in Parkinson’s and pt with history of EPSEs from neuroleptics
Drug interaction
Lithium –neurotoxicity
As with other antipsychotic drugs
Adverse effects: less anticholinergic, hypotensive, least epileptogenic BUT increased risk of EPSEs
clozapine- dibenzodiazepine
used for resistant psychosis atypical neuroleptic Adverse effects: Weight gain, agranuloctosis and neutropenia, sedation, postural hypotension, anticholinergic s/e.LESS EPSEs
Contraindicated in history of drug induced agranulocytosis
difference among antipsychotic drugs
low threshold in lowering seizure
tendency to cause metabolic and endocrine effects
tendency to cause cardiac toxicity (arrhythmias, QT prolongation)
effect of antipsychotics on different receptors
Muscarinic receptors-
anticholinergic-urinary retention, blurred vision, orthostatic hypotension, erectile dysfunction
Histamine receptors- sedation, antiemetic
Alpha adrenergic receptor- orthostatic hypotension
Serotonin receptors- psuedodepression
